https://github.com/cldellow/ersatz-table-valued-functions

A bad idea
https://github.com/cldellow/ersatz-table-valued-functions

sqlglot sqlite

Last synced: 20 days ago
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A bad idea

• Host: GitHub
• URL: https://github.com/cldellow/ersatz-table-valued-functions
• Owner: cldellow
• License: apache-2.0
• Created: 2023-01-21T17:45:49.000Z (almost 2 years ago)
• Default Branch: main
• Last Pushed: 2023-01-22T18:09:28.000Z (almost 2 years ago)
• Last Synced: 2024-10-04T22:16:36.442Z (about 1 month ago)
• Topics: sqlglot, sqlite
• Language: Python
• Homepage:
• Size: 11.7 KB
• Stars: 4
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# ersatz-table-valued-functions

[![PyPI](https://img.shields.io/pypi/v/ersatz-table-valued-functions.svg)](https://pypi.org/project/ersatz-table-valued-functions/)

[![Changelog](https://img.shields.io/github/v/release/cldellow/ersatz-table-valued-functions?include_prereleases&label=changelog)](https://github.com/cldellow/ersatz-table-valued-functions/releases)

[![License](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](https://github.com/cldellow/ersatz-table-valued-functions/blob/main/LICENSE)

A bad idea.

**ersatz** *(adj.)*: made or used as a substitute, typically an inferior one, for something else.

See also [datasette-ersatz-tablue-valued-functions](https://github.com/cldellow/datasette-ersatz-table-valued-functions/).

## Installation

Install this library using `pip`:

    pip install ersatz-table-valued-functions

## Usage

This library lets you rewrite queries like:

```sql

SELECT root, square FROM tbl_squares(3)

```

into queries like:

```sql

WITH _ersatz_1 AS (

  SELECT

    JSON_EXTRACT(value, '$[0]') AS "root",

    JSON_EXTRACT(value, '$[1]') AS "square"

  FROM JSON_EACH((SELECT tbl_squares(3)))

)

SELECT root, square FROM _ersatz_1

```

That is: it translates a query that _looks_ like it needs a table-valued function

into one that uses a scalar-valued function that returns a JSON 2D array.

To use it:

```python

from ersatz_table_valued_functions import rewrite

rewrite('SELECT root, square FROM tbl_squares(3)', { 'TBL_SQUARES': ['root', 'square'] })

```

## Development

To contribute to this library, first checkout the code. Then create a new virtual environment:

    cd ersatz-table-valued-functions

    python -m venv venv

    source venv/bin/activate

Now install the dependencies and test dependencies:

    pip install -e '.[test]'

To run the tests:

    pytest